Certain systems for dispensing individual portions of a heated liquid for consumption as a beverage have been in use since the late 1960s, including systems marketed by UUC UESHIMA COFFEE CO., LTD. and POKKA SAPPORO Food & Beverage Ltd., both of Japan. In order to dispense hot beverages, existing technologies heat entire cans and retain them at a substantially uniform temperature such that the inside and outside of the cans are at a temperature that can be comfortably held. Alternatively, heat-on-demand technologies may be employed, whereby an exothermic chemical reaction (as between calcium oxide or calcium chloride and water) is triggered within an inner chamber of a dual-chambered can, heating a beverage in an outer container, typically within 20-30 seconds.
A drawback of current modalities of dispensing single-serve hot beverages is the limited temperature of beverage that may be dispensed. In particular, since a beverage container is withdrawn from such an apparatus by hand, if the entire container were to be heated to a uniform temperature, that uniform temperature would have to be limited to a temperature comfortably handled by a person's hand. This is disadvantageous, however, because many beverages and other food items are preferably consumed at a temperature exceeding a comfortable handling temperature.
Drawbacks of the heat-on-demand paradigm include the complexity of manufacture and the uncertainty of the temperature at which the beverage is delivered, since the triggered chemical reaction adds a fixed, predetermined quantity of heat, such that the terminal temperature depends on the temperature at which the heating process starts.
It is desirable, therefore, that an apparatus and method allow for heating a beverage to higher temperatures, and for storing it over extended periods, yet, at the same time, allowing the beverage container to be comfortably handled by a person. It is particularly desirable that such an apparatus and method be suited to a variety of situations in which a consumer may wish to have ready access to a hot beverage. Such an apparatus and method are provided by the invention described below.